This invention relates to elevator lifting systems and more particular to a hydraulic piston elevator lifting system of at least two connected hydraulic piston cylinder devices.
In the past, there have been various hydraulic elevator lifting systems. By way of example, is U.S. Pat. No. 3,613,834 in which an elevator lift is illustrated. A pair of readily displaced hydraulic lifting cylinders are used to lift the elevator car. In another example, U.S. Pat. No. 3,968,860, a hydraulic elevator installation is illustrated. A pair of cylinders are utilized with a common plunger to control the vertical movement of the elevator.
Another example is shown by U.S. Pat. No. 3,534,664, in which a lift truck mast and ram assembly is disclosed. A series of laterally displaced rams supported by a base plate and connected in series to a hydraulic circuit, control the raising and lowering of the lift.
The present invention overcomes the problems of the past by utilizing a plurality of hydraulic piston cylinder devices interconnected in a unique manner with a control system to achieve lifting heights not previously attainable in prior elevator lift systems heretofore.